Current image sensors use a variety of methods for creating color separation. One such method uses the differences in absorption length in silicon of light of different wavelengths for color separation, such as in U.S. Pat. Nos. 5,965,875 and 4,613,895. In this regard, the incoming light is stored in separate regions of the substrate according to its wavelength, and the pixels are arranged so that each pixel receives each color at distinct depths of the silicon.
Another method of producing color separation in image sensors uses color filter arrays. In this regard, color filters are placed over the image sensor, and the color filter separates the incoming light so that particular colors are directed onto particular portions of the image sensor, such as is used in the well-known Bayer pattern. In this arrangement, each pixel receives only one color so that interpolation is needed when the entire image is created therefrom.
In co-pending U.S. application Ser. No. 10/636,410, filed Aug. 7, 2003, titled HYBRID TWO COLOR PER PIXEL ARCHITECTYURE USING BOTH COLOR FILTER MATERIALS AND WAVELENGTH DEPENDENT SILICON ABSORPTION, by Summa, the above methods are combined so that one photosensitive area receives each color at predefined depths.
Although the above method is satisfactory, they include drawbacks. Color cross-talk is an undesirable inherent feature of the above methods. Therefore, an apparatus and method are needed for overcoming the above drawback.